Heat rejection films are normally applied to the interior of flat glass windows to reduce the amount of infrared, visible light, and ultraviolet (UV) radiation entering windows. Such films are either dyed or metalized (which can be transparent to visible light) to convert incoming solar radiation to infrared radiation, which is then rejected back through the glass to the exterior. They usually cost 10-15 percent more than regular windows but can reduce energy loss by as much as 30-50 percent." Window film can save you some money.
To keep the sun's heat out of the house, a low-emissivity coating should be applied to the outside pane of glazed windows. If the windows are designed to provide heat energy in the winter and keep heat inside the house (typical of cold climates), the low-emissivity coating should be applied to the inside pane of glazed windows. Such films also reduce the amount of visible and ultraviolet light entering a window, and are often applied to reduce fading of the contents of a room. Silvered film may also be employed to the same end. New technology spectrally selective films that block certain wavelengths of the suns infra red energy reject solar heat without reducing natural light.
Security films are applied to prevent glass from shattering. Typically applied to commercial glass, these films are made of heavy-gauge plastic and are intended to maintain the integrity of glass when subject to heavy impact. The most robust security films are capable of preventing fragmentation and the production of hazardous glass shards from forces such as bomb blasts. Some companies have even experimented with bullet ballistics of multiple layers of security film.
These security films, if applied properly, can also provide protection for vehicles.These security films are often tinted and can be up to 400 micrometers (m) thick, compared to less than 50 m for ordinary tint films. If anchored correctly, they can also provide protection for architectural glazing in the event of an explosion. A layer of film (of 100 m thickness or greater) can prevent the ejection of spall when a projectile impacts on its surface, creating small dagger-like shards of glass that can cause injury.
Graphic design films are generally colored vinyl or frosted. Frosted finish films closely resemble sandblasted or acid-etched glass, while vinyl films are available in a range of colors. Both types of films are commonly used in commercial applications.
Privacy films reduce visibility through the glass. Privacy film for flat-glass commercial and residential applications may be silvered, offering an unimpeded view from the low-light side but virtually no view from the high-light side. It may also be frosted, rendering the window translucent but not transparent. Privacy films for automobiles are available in gradients of darkness, with the darker tints commonly known as "limo tint."
The thicker window films known as safety and security window film are designed to perform under extreme conditions, and as such there are specific standard criteria these films should meet, such as American standards ANSI Z.97, CPSC 16 CFR 1201, Cat II (400 ft-lb), and the British Standards BS 6206 (Class A, B, C). The European Committee for Standardization offer the EN12600 standard Classification of Resistance of Glazing to Impact. Often, building codes dictate that a film must have a report verifying that it has met at least one of these standards.
